Procraft, Could be we are both interested/working on the Holley Sniper two barrel injection using a modified stock intake? If so, the larger Sniper two barrel (550 849) has larger flange, than the Rochester or "Jeep" two barrel TBIs. This could cause throttle arm interference on the rocker cover, hence looking at the smaller TBIs. But only the mounting flange is larger, throttle plates appear about the same diameter? All support 350 horsepower. The; 550 849 Sniper flows; 350 CFM no information on the others yet. Talking to Holley on this. If using the smaller flange TBIs. On the stock Ford mounting flange. Thinking of screwing in aluminum threaded inserts, into the present carburetor mounting flange holes. Milling flat. That would leave a surface ready for redrilling and taping for new pattern.
Looked into milling the top of the stock manifold off, welding a four barrel adapter on. Problem is, there are two intake hold down bolts to deal with that, would be in the flange location (locat bolts to intake floor?).
For me, TBI is about getting clearance and drivability. Yes, I could just install another Weber two barrel but that would be without problems. I do have the Offenhauser with the four barrel carburetor. From the air filter base to the bottom of the hood, clearance is; 3 1/2 inch, above the choke horn is even less. Also considered removing the choke horn, and having no choke on the Holley carburetor for hood, and some type of air filter clearance. But......I need another inch of ground clearance. The engine needs to move up.
The car is not an Alpine, it is a Marcos. This particular car used the Ford V6. Using the site for engine information. Thank you for the help.
Steve V.